The field of the invention is collapsible stands. Such stands are typically tripods and are commonly used to support numerous objects.
One such assembly is shown in the Wang U.S. Pat. No. 4,905,946. Other methods for locking an element such as a leg in various fixed positions are shown in the following U.S. Pat. Nos.: 261,894; 496,834; 742,590; 772,293; 2,271,332; 2,353,513; 2,463,082; 2,556,995; 2,588,399; 3,419,295; 3,520,514; 3,804,355; 3,961,176; 4,150,733; 4,593,879 and 4,770,559.
For uses such as supporting a light fixture such as a halogen lamp, it is important that the legs be securely locked in a fixed position. Such stands are designed for long-term use, and the locking method should be one which would withstand many years of wear, be highly reliable, be easy to operate and which permits more than one possible position for support on an uneven surface such as a flight of stairs.